1. Field of the Invention
This invention relates to method and apparatus for producing fuel mixtures, and more particularly, relates to such method and apparatus for the production of microaerosol particles of water, fuel and/or oxidizer in an optimum mixture for internal combustion engines or burners.
The process of combustion of liquid fuel in an internal combustion engine or other burner is determined by the composition of the fuel mixture as well as the degree of atomization of the fuel. Even when the proportions of fuel and air are optimally chosen, there is still the problem of incomplete combustion and consequent diminished performance of the engine as well as pollution of the environment. Even in the case of an excess of oxygen in the gaseous phase of the mixture, the process of combustion is slow and proceeds at a high temperature.
In addition to certain optimal conditions pertaining to the fuel/air mixture, there are also desired optimum conditions relating to the water content in the fuel mixture. For instance, the water content in the fuel mixture modifies the process of combustion, and there is ample reason to attempt to obtain an optimum water content during the preparation of a fuel mixture in order to maximize engine performance and burning of the fuel as well as to minimize pollution of the environment.
2. Prior Art
Various attempts have been made in the prior art to achieve optimum air/fuel mixtures, including introduction of water into the mixture, and to thoroughly atomize or vaporize the mixture before introducing it into the cylinders of the engine.
For instance, U.S. Pat. No. 3,911,871 describes a system for adding water to the intake system of an engine, and uses a vacuum controlled injector which passes water over an ultrasonic atomizer 52 to atomize the water.
U.S. Pat. No. 4,183,338 uses exhaust gas and vacuum condition at the PCV inlet to achieve a fluidic control of the flow of fuel into the engine. Vortex chambers are used as the controlling devices in conjunction with exhaust gas pressure and PCV vacuum.
U.S. Pat. No. 4,324,209 describes an apparatus for obtaining an homogenized fuel/water mixture and then vaporizing it before admixing the mixture with air for introduction into the engine. The apparatus includes a transducer 313 in a chamber into which fuel and water are introduced to be homogenized. The homogenized mixture is then passed through a steel wool baffle 18 to diffuse the fuel/water mixture.
Other attempts at supplying water to internal combustion engines are described in U.S. Pat. Nos. 2,218,522, 2,352,267, 3,325,976, 3,608,529, 3,980,055, 4,005,683, 4,018,192 and 4,030,457. The simple addition of water, however, does not give satisfactory results. For instance, this step alone does not result in significantly higher efficiency of the engine. Thus, although the introduction of water as steam or liquid does reduce atmospheric contamination caused by unburned pollutants in the products of combustion, and the lowering of the temperature of the combustion process, the problem of preparation of the optimal fuel mixture still remains.
A recent effort at solving the problems relating to fuel mixtures and their preparation is described in U.S. Pat. No. 4,048,963. However, this arrangement does not give completely satisfactory results. The ultrasonic vibration produces an emulsion, but the emulsion burns slowly and does not significantly increase the efficiency of the engine, which "runs with the same power as on straight gasoline". The inhomogeneity of the emulsion particles of the mixture of fuel and water implies the shortcomings of its application. Besides, preparation of the fuelwater emulsion requires a special device and additional energy expenditure.
The prior art thus describes several methods and devices for the injection of water and/or the control of injection with regard to the cycle of the engine. However, in all cases the fuel and water are separate particles, and the resultant fuel mixture is inhomogeneous.